PREMISE
Taken directly from the PDF. I couldn’t have said it any better, Kudos to Peter for wordsmithing that one.

OSR Bonus Cards are a fun fantasy gaming aid designed to give low- to mid-level characters an extra edge without unbalancing the game. The group receives a number of cards (determined by a die roll) at the beginning of the night. Each card provides small bonuses that may be used over the course of the session. Some bonuses are generic (+1 to-hit, +1 to saving throw, etc.) while others are class-specific (bonus to Turn undead, +10% to a thief skill, etc.). OSR Bonus Cards are a great way to shake up the game and add some randomness to the typical resource management systems we’ve all grown accustomed to.

QUALITY
This product only comes in a digital format, which is a shame. These cards could stand to be made of a high-quality card stock as they will take some abuse at the table. Aside from that, the quality of the art is very old school in theme and very appropriate for this type of product. Although it reminds me a lot of the old Marvel Superheroes game art and less like fantasy art, but all-in-all the art is nice.

MECHANIC OVERVIEW
There are three ways to introduce the cards into your game. Two of the three methods involve allowing each player to roll a particular set of dice and take that number of cards. The third allows players to draw a card on a roll of a natural 20. Cards are played during a player’s turn or in response to particular situations where the play of a card would be appropriate.

PROS
The cards break up the monotony of your standard OSR game. They give players a possible edge during tricky situations. Who doesn’t love a good ‘ole bonus here and there.

CONS
Causes players to think on the meta level to capitalize on the card’s abilities. They are a limited resource that players will have to manage in addition to their character.

PARTING SHOTS
I like the idea of the cards, but they are just not my thing. While I don’t think they will skew the game balance in any meaningful way, they are just another thing at the table. I think my players focused on the game and the story, but the bits and bobs at the table. Conversely, I have a friend (you know who your are) that swears by these cards! He uses them in every game he runs and he loves the idea that they break up the monotony of his OSR games. Your mileage will vary, but these may be just the add-on you have been looking for.